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31 Cards in this Set
- Front
- Back
What are the 3 layers of the eye?
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Outer Fibrous, Middle vascular, Inner nervous
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What are the 3 layers of the Sclera?
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Episcleral, Substantia propria, suprachoroidal lamina
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What is Tenon's Space?
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Space between episcleral and substantia propria layers - allows eye to rotate freely
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What is the Canal of Schlemm and where is it located?
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Aqueous humor drains into ciliary veins here - sclerocorneal junction
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What are the 6 layers of the cornea?
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Anterior corneal epithelium (stratified squamous with microvilli on superficial cells for protective tear coating- 6 layers)
Bowman's Membrane - homogenous collagen fibers (stability, strength of cornea) Corneal Stroma - Mainly collagen I but also has types III, V, VI. Parallel arrangement of collagen fibers gives transparency |
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What is Decemet's Membrane?
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Posterior limiting lamina of cornea with homogenous collagen filaments
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What are the two layers of the choroid?
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Choriocapillary, Bruch's Membrane (between retinal pigment epithelium & choroid)
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What are the major components of the iris?
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Anterior limiting membrane - incomplete & fenestrated, stellate fibroblasts
Stroma - collagen, fibroblasts, melanocytes (eye color) Pigmented posterior epithelium 2 muscles - dilator pupillae, sphincter pupillae |
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What is the nervous innervation for each of the iris muscles?
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Sphincter pupillae - CN III
Dilator pupillae - Sympathetics |
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Describe the retinal layers
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Outer pigment epithelium and inner sensory retina
Stratified layer of nervous cells |
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Explain Retinal Detachment
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Separation of photoreceptor layer from pigment layer
If not re-attached, degeneration of rods and cones |
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What the the layers of the retina from inside to outside (where light hits)?
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Inner limiting membrane - Optic nerve layer - ganglion cell layer - inner plexiform (synapses between ganglion cells and bipolar cells) - inner nuclear (bipolar/horizontal cells) - outer plexiform (synapses between horizontal cells & photoreceptors) - outer nuclear (rod/cone granules)- outer limiting - rods & cones - pigment cell layer
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Describe the retinal pigment epithelium
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basement membrane blends with Bruch's membrane
Site of Vit A esterification Microvill surround photoreceptors and have phagocytic function Blood-retinal barrier |
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What are the different parts of a photoreceptor cell?
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Outer segment (photoreceptor disk - contains photosensitive chemicals), modified cilia (connects segments), inner segment, nuclear region, synaptic region
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What is a major structural difference between rods and cones?
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Rods have a cylindrical outer segment while cones are more pointed
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What are major differences between rods and cones?
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Cones - thick, short, conical outer segment, concentrated in fovea, photopigment is iodopsin
Rods - sense light intesity, more in the periphery, photopigment is rhodopsin |
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What are Muller's Cells and where are they found?
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Retinal support cells that form outer limiting membrane and rest on the inner limiting membrane,
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What is unique about the macula area of the retina?
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Only contains cones
Yellow color due to xanthophil pigment of ganglion cells One photoreceptor to one ganglion |
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Blood supply of Retina?
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Artery & vein enter with optic nerve
Form a plexus of capillaries between vitreous and inner limiting membrane Rods & cones supplid by choroidal vessels Layers 1-5 - Chorocapillary supply Layers 6-10 - Central artery of optic nerve (continuous as retinal a.) |
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Describe the different parts of the lens
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Capsule - type IV collagen, glycoproteins
Subcapsular epithelium - simple cuboidal, only on anterior side Fibers - long & with crystallins |
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Describe the flow of aqueous humor
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Ciliary body to anterior chamber to Canal of Schlemm at sclerocorneal junction for drainage
Abnormal drainage here causes intraoccular pressure to rise (Glaucoma) |
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What layers make up the tympanic membrane?
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Outer layer - skin
Middle - connective tissue Inner - simple cuboidal cells Attached to malleus ossicle (linked to oval window) |
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What are the contents of the middle ear?
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Ossicles - malleus, incus, stapes
Muscles - Tensor tympani, Stapedius - limit vibration of membrane & stapes during loud noise Oval window, round window |
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What makes up the Bony Labyrinth of the inner ear?
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Semicircular canals, vestibule, cochlea
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What makes up the Membranous Labyrinth of the inner ear?
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Semicircular ducts, Utricle, Saccule, Cochlear duct
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Describe the cochlear duct
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Bounded by Reissner's membrane (vestibular) and basilar membrane and stria vascularis. Contains the organ of Corti (containing neuroepithelial hair cells and support cells) which is covered by the tectorial membrane
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How does sound conduction work?
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The oval window sets up sound waves with cochlea. The vibration of the basilar membrane causes hair cells to bend by a shearing force as they pull on the tectorial membrane, causing firing of the cochlear nerve
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What is the Macula of utricle?
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Receives the utricular filaments of the vestibulocochlear nerve.
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What is the Helicotrema?
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It is the communication point of the scala tympani with the scala vestibuli at the apex of the cochlea
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What are the Cristae ampullares?
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similar to maculae, has a conical form called cupula
Receptors are sensitive to rotational acceleration They are located in the ampulla of the semicircular ducts |
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What are maculae?
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Receptors found on the walls of the saccule and utricle.
Characterized by specialized microvilli with a single cilium (kinocilium) These receptors synapse with the vestibular component of CN VIII |